Passenger seats in premium classes aboard commercial aircraft and other conveyances can be adjustable to achieve various sitting positions. In aircraft, passenger seats typically adjust between an upright sitting position for taxi, take-off and landing (TTOL), and a less upright, more comfortable sitting position during flight. In super premium classes on long haul flights, where passenger space is at a maximum, passenger seats can adjust to a flat horizontal bed.
Passenger seats typically include at a minimum a seatback and a seat bottom or seat pan. In the TTOL position, the seat pan may be at a shallow angle to horizontal and the seatback near vertical, thus positioning the sitting passenger in the optimum position to support the upper body, neck, and head in the event of a sudden deceleration event. In the full sleeping position, the seatback and seat bottom may be coplanar and horizontal. Passenger seats can optionally include legrests and armrests, which together with the seatback and seat pan adjust in the various sitting positions to maximize support and comfort.
Conventional seatbacks are unsegmented and either linear or fixed in curvature. As such, seat adjustability is limited to the achievable angles between the seatback and the seat pan. Considering that upper body curvature may vary between passengers, and that single angle seat adjustability cannot achieve all desirable intermediate sitting positions, what is needed is a multi-angle adjustable seat. Such a desirable seat would allow full customization in achievable seat angles, a variety of intermediate sitting positions, and in a mechanical assembly without the need for multiple actuators.